This invention relates to a large-bracted dogwood, which is the result of an extensive program of interspecific hybridization to produce certain characteristics which I believe are desirable in dogwood trees and in fact have established this one as an example of a series of dogwood trees, which embody my own concept as to desirability and other characteristics which make the same commercially desirable and thus potentially for widespread dissemination and use by the public.
During the course of my development, I have used an unnamed seedling of Cornus kousa Hance as the seed parent and the pollen parent Cornus florida L. cv. Cherokee Princess, none of the above being patented.
Some of the characteristics which I have hoped to provide and which this particular cultivar does in fact exemplify, are the novel floral characteristics and growth habit which are due to the hybrid nature of the plant.
Since this particular tree is one of a group, which will be further referred to and is distinct from either of the parents, I have chosen to use the name. `Rutfan` as the basis for its distinction in the trade and as such the same will be known in commerce by that name.
This hybrid is, I believe, entirely new in horticulture and botany, as to make it necessary to compare only with the parental species as opposed to other cultivars, since the latter do not exist as far as I am aware.
It is important to note the aspect of the overwintering buds of my new cultivar, as compared with the parent plants, noting that the peduncle supporting an overwintering flower bud of C. florida is elongated such that the bracts on the peduncle are positioned well below the flower head and that the true flowers are well developed and are tightly enclosed overwinter by two sets of opposing floral bracts that persist in the spring and enlarge to provide the floral display. However, in C. kousa, the peduncle supporting an overwintering flower buds is very short, the flowers in the flower head are not well developed, the two sets of opposing floral bracts that clasp the true flowers are minute, and the flowers are tightly enclosed overwinter by the uppermost set of bracts on the peduncle. These bracts drop quickly in the spring as the peduncle begins to elongate and the various components of the flower head enlarge and/or resume development. Plants of C. kousa flower a month later in the spring than do plants of C. florida since the short peduncle, relatively undeveloped flowers, and the minute floral bracts require that much more time to mature developmentally.
In the hybrid of the instant cultivar, an intermediate condition between C. florida and C. kousa prevails in that the peduncle supporting an overwintering flower bud of my hybrid is elongated such that the upper set of bracts is positioned on the peduncle a short distance below the flower head but still close enough to partially enclose the flower head overwinter, along with the fairly well developed floral bracts which enclose the true flowers about 96-99% but not as fully, or tightly, enclosed as is the case in C. florida. Thus the overwintering flower buds in my hybrid are partially protected overwinter by both the bracts, which drop early in the spring, and by the floral bracts which persist and enlarge to provide the floral display.
In summary, it may be stated that my new hybrid represents a new large-bracted dogwood, hybrids of the species C. kousa and C. florida never having been reported previously as far as I know. My new dogwood is a vigorous and highly floriferous, small, flowering tree which develops a form or outline more nearly like plants of the parental American species, C. florida rather than being upright as is true for most plants of C. kousa. Typically however plants of my new cultivar are more densely branched and foliaged close to the ground than are plants of C. florida.
Thus the plants of my new cultivar are intermediate to those of the two parental species with regard to such horticultural characteristics as vigor, branch diameter, time of flowering and of floral display (floral bracts), number of flower heads per tree, number of true flowers per flower head, length of peduncle and size of overwintering flower buds. Additionally position of bracts on the peduncle of the overwintering flower buds and size and stage of development of the true flowers and the floral bracts in the overwintering flower buds are different.
My new hybrid is highly sterile.
In order to summarize the various characteristics which are notable in my new cultivar, I have broken down the various aspects of the same as respects its tree shape, flower buds, bracts and other characteristics as will be set forth hereinafter in the specific succinct summaries noted below.